
     //计数器
    function countDown() {
      var target = new Date(2021, 10, 21);
      var target_t = target.getTime();
      var now_t = Date.now();
      var reduce_t = target_t - now_t;
      var second = parseInt(reduce_t / 1000 % 60)
      var minute = parseInt(reduce_t / 1000 / 60 % 60);
      var hour = parseInt(reduce_t / 1000 / 60 / 60 % 24);
      var day = parseInt(reduce_t / 1000 / 60 / 60 / 24);

      if (second < 10) {
        second = "0" + second;
      }
      if (minute < 10) {
        minute = "0" + minute;
      }
      if (hour < 10) {
        hour = "0" + hour;
      }
      if (day < 10) {
        day = "0" + day;
      }
      day_ele.innerHTML = day;
      hour_ele.innerHTML = hour
      minute_ele.innerHTML = minute;
      second_ele.innerHTML = second;

    }
    setInterval(countDown, 1000);
    countDown();
    //
    
    
      
   


